The present invention relates to a silver halide photosensitive material automatic developing apparatus.
Conventionally, silver halide photosensitive material is processed in a processing solution by an automatic developing apparatus. It is common that the processing agent is replenished into the processing tank so as to maintain the activity of the processing solution in the processing tank at a predetermined value. Conventionally, the following replenishing system is employed to replenish the processing agent into the processing tank. The processing agent is previously dissolved. The thus obtained replenishing solution is supplied into the processing tank. This method is commonly used.
However, according to this commonly used replenishing method, the following problems may be encountered. When the color development replenishing solution stays in a color development replenishing solution tank over a long period of time, the color developing agent is necessarily oxidized. When the oxide of a color developing agent is deposited on the photosensitive material, the quality of a developed image is deteriorated in a low density portion on the photosensitive material, especially in a white portion on a photographic paper.
In order to avoid a long stay of the color development replenishing solution in the color development replenishing solution tank, a method has been disclosed recently by Japanese Patent Publication Open to Public Inspection No. 11954/1993, in which the processing agent for processing silver halide photosensitive material is solidified, and the solid processing agent is directly supplied into the processing tank so that the components of the processing agent can be replenished.
However, the present inventors have found that the following problems may be encountered even when the above method is used, in which the solid processing agent is directly supplied into the processing tank.
When an amount of photosensitive material to be processed in one day is too small, the color developing solution in the processing tank is not replaced with a new one. Accordingly, the color developing agent in the solution filled in the color developing tank is necessarily oxidized. As a result, the oxide of the developing agent is deposited on the photosensitive material. When the oxide of a color developing agent is deposited on the photosensitive material, the quality of a developed image is deteriorated in a low density portion on the photosensitive material, especially in a white portion on a photographic paper.
In Japanese Patent Publication Open to Public Inspection No. 119454/1993 described before, there is no description of the above problems, much less a specific method to solve the problems.
It is an object of the present invention to solve the problem in which the oxide of the color developing agent is deposited on the photosensitive material and the quality of an image formed in a low density portion of the photosensitive material is deteriorated.